Compound X: Compound X is chloromethane (also known as methyl chloride), which is formed when chlorine replaces a hydrogen atom in methane (the first homologous member of alkanes) in the presence of sunlight.

Lewis Dot Structure of Chloromethane:
- In the Lewis dot structure, the chemical symbol of the element is represented by its atomic symbol, and valence electrons are represented as dots around the symbol.
- Chloromethane has the chemical formula CH3Cl.
- Chlorine (Cl) has 7 valence electrons, while hydrogen (H) and carbon (C) have 1 and 4 valence electrons, respectively.

Lewis Dot Structure of Chlorine (Cl):
- Chlorine has 7 valence electrons, so it is represented as Cl with 7 dots around it.

Lewis Dot Structure of Hydrogen (H):
- Hydrogen has 1 valence electron, so it is represented as H with 1 dot.

Lewis Dot Structure of Carbon (C):
- Carbon has 4 valence electrons, so it is represented as C with 4 dots.

Lewis Dot Structure of Chloromethane (CH3Cl):
- Carbon in chloromethane is bonded to three hydrogens and one chlorine atom.
- The Lewis dot structure of chloromethane can be represented as follows:
- The carbon atom is represented as C with 4 dots.
- The three hydrogen atoms are represented as H with 1 dot each.
- The chlorine atom is represented as Cl with 7 dots.

Explanation:
- In chloromethane, chlorine (Cl) replaces one of the hydrogen atoms in methane (CH4).
- Chlorine is a halogen and has a higher electronegativity than hydrogen.
- In the presence of sunlight, the highly reactive chlorine atom abstracts a hydrogen atom from methane, resulting in the formation of hydrogen chloride (HCl) and chloromethane (CH3Cl).
- The reaction can be represented as follows: CH4 + Cl2 -> CH3Cl + HCl.
- The Lewis dot structure of chloromethane shows that the carbon atom is bonded to three hydrogen atoms and one chlorine atom.
- The chlorine atom gains an electron from the carbon atom, forming a covalent bond.
- The chlorine atom now has an octet of electrons, while the carbon atom and the three hydrogen atoms have a duet of electrons.
- The Lewis dot structure helps visualize the arrangement of valence electrons in chloromethane and understand its molecular structure.

Overall, the replacement of a hydrogen atom in methane by chlorine in the presence of sunlight leads to the formation of chloromethane (CH3Cl), which can be represented using Lewis dot structure to depict the arrangement of valence electrons in the molecule.